Vibration at 40 km/h


#1

Hi everyone.

My Hyundai Sonata 2008 vibrates when driving at 40 km/h. Steering wheel doesn’t shake, only car vibrates. And this happens regardless of pressing gas pedal or not. Front wheels are balanced(as the car is front wheel drive) yesterday but no success.


#2

“Front wheels are balanced (as the car is front wheel drive) yesterday but no success.”

All 4 wheels need to be balanced, no matter whether a vehicle is FWD, RWD, or 4WD.

If you had a RWD vehicle, would you think that only the rear wheels needed to be balanced?


#3

Vibration at that speed is less likely a unbalanced tire than something else. I’d look for an out of round tire with a failed belt or a bent wheel or a failing wheel bearing or a loose wheel. Your tire tech most likely would have told you about these if the fronts were at fault. It is VERY obvious on a spinning balancer.

Do what @VDCdriver suggests and balance the rears, if you don’t find a problem, have the car inspected. Vibrations are more than annoying, they are a sign that something potentially serious is wrong. Be ready to pay the tech for his time.


#4

40 kmph = 25 mph. That’s a little slow for a wheel end vibration. Though it might be an out of round wheel, the car should also vibrate in the 50 to 70 mph range. (85 to 115 kmph).

If it doesn’t, I suggest looking at a CV joint.


#5

Are the tires the same brand and model? I put 2 tires on an 86 Dodge Colt and the car would shake violently at 25-40 mph. The new tires were the same size (155R13) than the original tires, but the difference in actual diameter was enough to cause the shaking. Four matching tires solved the problem, since then I’ve replaced tires 4 at a time.

Ed B.